Learn English – Are “betwixt”, “trebble”, etc., acceptable in American English

american-englishbritish-englishformality

I grew up speaking British English. The words I learnt were occasionally marked off in papers, despite their being English words. Are words like betwixt, trebble, learnt acceptable in papers for English classes for professors in America, specifically Texas?

Best Answer

"Betwixt" is archaic and highly marked for American English, but not technically wrong.

"Learnt" is non-standard, but intelligible and probably not a problem.

I've never heard or seen the word "trebble", and would mark it as an error in any piece of formal writing.